OFDMA communication apparatus

Abstract

An OFDMA communication apparatus is disclosed that operates under media access control based on an OFDMA standard and modulates transmission data into an OFDMA signal. The OFDMA communication apparatus includes a preamble generating unit that generates plural types of preamble patterns; a broadcast generating unit that generates broadcast data; a burst generating unit that generates a data burst according to the transmission data; a data multiplexing unit that generates multiplexed data by multiplexing the data generated by the preamble generating unit, the broadcast generating unit, and the burst generating unit on a predetermined physical layer format; an OFDM unit that performs orthogonal frequency division multiplexing on the multiplexed data using plural sub carriers; a carrier assigning unit that assigns the preamble patterns to at least four sub carrier groups; and a symbol assigning unit that divides the preamble patterns into plural sub pattern element groups that are time-multiplexed on the predetermined physical layer format.

1 . A radio communication apparatus that modulates transmission data into an OFDMA signal and transmits the OFDMA signal, the radio communication apparatus comprising:
 a preamble generating unit that generates a plurality of types of preamble patterns that include synchronization data for synchronizing frequency and time in a receiving apparatus;   a carrier assigning unit that assigns the plurality of types of preamble patterns to sub carrier groups each made up of adjacent sub carriers;   a data multiplexing unit that assigns the plurality of types of preamble patterns to the sub carrier groups according to instructions of the carrier assigning part;   an OFDM unit that performs orthogonal frequency division multiplexing on the preamble patterns assigned to the sub carrier groups using a plurality of sub carriers.   
     
     
         2 . A radio communication apparatus that modulates transmission data into an OFDMA signal and transmits the OFDMA signal, the radio communication apparatus comprising:
 a carrier assigning unit that assigns a plurality of types of preamble Patterns that include synchronization data for synchronizing frequency and time in a receiving apparatus to four or more sub carrier groups;   a preamble generating unit that generates the plurality of types of preamble patterns according to instructions of the carrier assigning unit;   a symbol assigning unit that divides each type of preamble patterns of the plurality of types of preamble patterns into a plurality of groups of sub pattern elements and time-multiplexes the plurality of groups of sub pattern elements;   a data multiplexing unit that time-multiplexes the plurality of groups of sub pattern elements according to instructions of the symbol assigning unit;   an OFDM unit that performs orthogonal frequency division multiplexing on the preamble patterns time-multiplexed using a plurality of sub carriers.   
     
     
         3 . The radio communication apparatus as claimed in  claim 2 , wherein
 each of the four or more sub carrier groups includes a plurality of sub carriers that are not adjacent to each other.   
     
     
         4 . The radio communication apparatus as claimed in  claim 2 , wherein
 each of the four the four or more sub carrier groups includes a plurality of sub carriers that are adjacent to each other.   
     
     
         5 . The radio communication apparatus as claimed in  claim 2 , further comprising:
 a carrier stopping unit that controls a DTX (discontinuous transmission) command for at least one of the four or more sub carrier groups to be activated at the preamble generating unit and stops transmission of sub carriers belonging to the at least one of the four or more sub carrier groups.   
     
     
         6 . The radio communication apparatus as claimed in  claim 2 , further comprising:
 a preamble stopping unit that directs null data to be multiplexed on a preamble pattern area on a predetermined physical layer format corresponding to at least one of the four or more sub carrier groups, and stops transmission of at least one of the preamble patterns corresponding to the preamble pattern area.   
     
     
         7 . The radio communication apparatus as claimed in  claim 6 , further comprising:
 a band control unit that arranges a data burst transmission area of the at least one of the four or more sub carrier groups to be used as a data burst transmission area of at least another one of the four or more sub carrier groups.   
     
     
         8 . The radio communication apparatus as claimed in  claim 2 , wherein
 the four or more sub carrier groups are assigned to a plurality of sectors into which an administered cell is divided.   
     
     
         9 . A radio communication method for modulating transmission data into an OFDMA signal and transmitting the OFDMA signal, the radio communication method comprising:
 generating a plurality of types of preamble patterns that include synchronization data for synchronizing frequency and time in a receiving apparatus;   assigning the plurality of types of preamble patterns to sub carrier groups each made up of adjacent sub carriers; and   performing orthogonal frequency division multiplexing on the preamble patterns assigned to the sub carrier groups using a plurality of sub carriers.